1. Field of the Invention
The present invention relates to image forming systems including image forming apparatuses and information processing apparatuses, to information processing apparatuses, and to methods for processing image forming data for use in image forming systems. More specifically, the present invention relates to an image forming system, an information processing apparatus, and a method for processing image forming data in which image-forming print data generated by the information processing apparatus is transmitted to an image forming apparatus and the image forming apparatus forms an image based on the print data.
2. Description of the Related Art
Conventionally, for example, when an information processing apparatus, such as a personal computer, uses a printer to print out print data, such as a document or an image, which is edited by an application for document editing or image editing, it is common for the information processing apparatus to perform quantization and compression in order to reduce the size of print data to be transmitted to the printer. In this case, the quantization method is determined in response to printing conditions set by a user or based on the content of the print data, the determined quantization method is used to quantize the print data, and the quantized print data is compressed with a predetermined compression method before being transmitted to the printer (see, for example, Japanese Patent Laid-Open No. 10-13674).
Currently widely used quantization methods are dithering and error diffusion. It is common to use dithering to perform quantization for print data such as text and flowcharts, and it is common to use error diffusion to perform quantization for print data such as photographs.
When the quantized print data is compressed, in general, print data quantized by dithering, which uses a combination of patterns, tends to have a compression rate higher than that of print data quantized by error diffusion, although the compression rate depends on the content of the print data.
Various types of interfaces can be used for the information processing apparatus (host computer) to transmit print data to the printer. Currently widely used interfaces include USB (universal serial bus) 1.1, USB 2.0, and IEEE 1284 (parallel port standard). In addition, other interfaces in use include IEEE 1394, Bluetooth, IrDA (Infrared Data Association), and wireless LANs. Many printers support a plurality of interfaces for transmitting print data. A user can select an interface for transmitting print data from among the supported interfaces.
As described above, there are a plurality of interfaces for use in transmitting print data from a host computer to a printer. A speed at which the print data is transmitted to the printer, that is, the time required to transmit the print data to the printer, greatly differs depending on the interface used.
The print data that passes through the interface connecting the host computer and the printer has a relatively large size. Thus, even if the host computer and the printer have high processing speeds, in the case of using, for example, a low speed interface, such as Bluetooth, which is inferior to other interfaces (e.g., USB) in speed and transmission range, the low speed interface requires a much longer time for printing to complete, compared with the high speed interface.
When, in order to reduce data size, a compression method enabling a high compression rate is used even if the interface is capable of high speed transfer, decompression requires a great amount of time. Accordingly, simple reduction of the data size does not always shorten the time required to complete printing. However, processing in the present image forming system is not performed with interface features considered.